The patent is defined as the exclusive right over an invention that is granted and administered by the competent state authority in the particular country. According to the law, a patentable (registerable) invention is one that meets all three main criteria: to be new, to have an inventive step and to be industrially applicable. In general, any new inventive solution of a particular problem in the sphere of the engineering can be defined as an invention. If necessary and at the request of the applicant, the inventions can also be protected by registering them as a Utility Model.

Besides the protection of the technical qualities as a patent, the other objects of Industrial Property can be used to protect the rights of the proprietor over the invention. They are in regard with the trade name as a mark (according to the Trademark and Geographic Indications Act) and the external design and appearance of the product, through its registration, as an Industrial Design (according to the Industrial Design Act).

General information

The obtained patent for an invention is a strong and reliable business tool, through which the applicants gain monopoly rights over a qualitatively new technology or market product through which they can add an additional market share or realize additional income through the licensing tool.

Determining whether the invention is novel

The invention may be novel if it is found that it it is not part of the prior art. In general, the prior art is related to all applicable or relevant technical knowledge and/or experience that is available to a wide range of specialists, worldwide, before the priority date of filing the specific patent application.

The state of the art includes: any kind of technical or non-patent literature, as well as already issued patents for inventions (valid or expired) and patent applications that are connected with the use of the invention. To some extend, the World Wide Web can also be a source of information on the current state of the art.

Determining whether the invention has an inventive step

It can be assumed that the invention has an inventive step, if it would not be obvious for a person skilled in the art that it follows from the state of the prior art. The requirements for an inventive step ensure that the eventual grant of a patent will be only for a real creative solution of a specific technical problem, and not for modifications of a pre-existing state of the art that a person with average technical skills could easily make.

Determining whether the invention has an industrial applicability

The patentability of a particular invention is also based on its industrial applicability. The presumption is that each patented invention must be useful, as well as provide an effect of its future applicability in solving a technical problem. The term "industrial applicability" should be perceived in the most general sense as a quality or feature and is different from the intellectual activity. It includes a wide range of technical activities related to the economic life.


The registered patent for an invention provides the holder with exclusive rights, which include the right to use the invention, to prohibt third parties to use it without the consent of the patent proprietor and the right to dispose of the patent. The right not to allow the use of the invention without his permission by third parties in the production and trade activities (including production, sale, import or export) is for a period of time, which might be up to 20 years starting from the priority date of entry of the application for patenting.

 However, in rare cases, patents that are already owned by others may cover or supplement partially your invention. In these cases, it is recommended to enter into a license agreement so that you can use the previously patented invention of the other owner in order to use yours for commercial purposes, and the opposite hypothesis is possible. Only the patent claims in the granted patent for an invention determine its legal scope of protection.


Globally, it has been accepted as a standard term of patent protection for inventions of the order of 20 years. This period starts from the priority date of filing the application at the Patent Office. It is important to note that the conditions for timely payment of the due fees for maintenance (renewal) of the patent have to be observed. Failure to comply with this condition on a regular basis leads to untimely expiration of the patent for the respective territory for which it is registered. In certain countries, the protection of a patented invention may be extended beyond that 20-year period. In the presence of special circumstances may be issued a Certificate of Supplementary Protection (SPC). For example, it is applicable to patents for pharmaceutical products due to their delayed commercialization due to the need for additional technological time for obtaining marketing authorization from the state and competent authorities. The validity of the Supplementary Protection Certificate is limited to 5 years.

Territorial scope of the exclusive rights acquired through patenting

The registered patents for inventions have not only temporal but also territorial nature of the rights they confer. In practice, this means that the patented invention has protection only in the countries (and/or regions) in which it has received registration (protection). Therefore, if it is not patented in the territory of a country, the invention will not be protected on the territory of that country. Such a circumstance will enable any interested person to use (manufacture, market, import or export) this invention in the given country.


There are three ways to protect the rights over an invention abroad.

– By national order - by filing separate applications for patenting the invention at each national patent office of the countries in which protection is sought. This approach may lead to certain procedural complications, such as the involvement in each country of different patent attorney; the filed applications must be in the official (working) language of the local patent office; payment in each country of the necessary filing fees; fulfillment of certain specific requirements under the national law. For the territory of the Republic of Bulgaria, the inventors must file a patent application at theBulgarian Patent Office. Choosing this way of protecting patent rights abroad can be too slow and expensive given the large number of countries where protection is sought.

Regionally - in cases where several countries are members of one of the regional patent systems. Such are, for example, the countries that are members of the European Patent Convention (EPC). In these cases, it is possible to apply for a patent which to be in force in some or all of them. Such protection is realizable by filing only one single patent application at a regional patent office - for example, filing an European patent application at the European Patent Office (EPO).

Internationally - The Patent Cooperation Treaty (PCT) provides broad opportunities for protection of a patent for an invention in any Member State, by filing only one international request for a PCT application. For those entitled to file such international (PCT) patent applications, the requirement is to be a national (or resident) in one of the Contracting States or to have a real (effective) business activity in such a State. Such international (PCT) applications may be filed through: the national patent offices; the regional patent offices. These offices are called recipients. The application can also be filed directly at the World Intellectual Property Organization (WIPO) in Geneva, which is also the receiving office.

Patent Bureau Plovdiv